KANSAS CITY -- The weather is getting hotter and so is Chris Sale.

In his 300th career appearance, Sale turned in a truly dominating complete-game performance even by his lofty standards. The Royals had little chance on Wednesday night as Sale never allowed a runner past first base in an 8-0 Red Sox victory at Kauffman Stadium.

As good as he was through seven innings, Sale turned it up another notch in the eighth with an immaculate inning -- nine pitches and nine strikes. He struck out 12, giving him double-digit strikeouts in six of his last seven outings.

• Box score

In fanning Royals Kelvin Gutierrez, Nicky Lopez and Martin Maldonado, Sale repeated a feat he did just 28 days ago, on May 8 against the Orioles. The only other pitcher to do it twice in the same season was Hall of Famer Lefty Grove, against the Indians on Aug. 23, 1928, and the White Sox 35 days later, on Sept. 27.

The Red Sox also provided Sale with some rare offensive support. He came into the game receiving just an average of 3.03 runs to work with over 12 starts. It all added up to Sale (2-7) getting his first victory since May 3, when he defeated the White Sox. 

With the three-hitter, Sale recorded the third shutout of his career.

“I felt like I was able to throw my changeup for a strike a little bit better,” Sale said. “My slider was as good as it has been. As the game went on, I gained momentum and felt stronger.”

Red Sox manager Alex Cora had initial thoughts of limiting Sale to eight innings. Cora and Sale talked after the seventh inning, and Cora said he wanted to see how the eighth would go.

But after Sale breezed through the eighth with nine consecutive strikes, Cora wasn’t about to deny him a complete game opportunity. Sale needed just 102 pitches to go the distance. His game score of 93 was the best of his career. He had three previous scores of 92 (May 12, 2013, June 19, 2015 and April 15, 2016).

While Sale’s 17-strikeout performance against Colorado on May 14 was certainly impressive, he said Wednesday’s effort was even more special. Sale was able to give the Red Sox bullpen a day off as the club prepares for a committee pitching approach in Thursday’s series finale.

“Anytime you can finish a game, that’s what we sign up for,” Sale said. “[Catcher] Sandy [Leon] can read my mind, it seems. He put down all the right fingers and I just followed his lead.”

The Royals felt Sale’s efficiency with the changeup was a huge key in making the lefty ace even tougher than usual.

“He wasn’t just a two-pitch pitcher,” Royals center fielder Billy Hamilton said. “He had the changeup going, too.”

While Sale was the focal point, the Red Sox offense was able to put its pitcher in a comfortable spot. Rafael Devers had a homer, a double and three RBIs, while Jackie Bradley Jr. contributed a three-run double in a four-run fifth.

Devers is hitting .338 over his last 15 games with 11 extra-base hits, 16 RBIs and 17 runs scored.